<html>
  <body>
    <audio src='foo'></audio>
    <audio id='moved' src='audio-6seconds.ogg'></audio>
    <iframe></iframe>
  </body>
  <script>
    const audio = document.getElementById('moved');

    function moveAudioToSubframe() {
      const frame_document = window.frames[0].document;
      frame_document.body.appendChild(frame_document.adoptNode(audio));
    }

    async function play() {
      await audio.play();
      return true;
    }
  </script>
</html>
